Scale block I/O

Docker compatibleDocker Swarm not yet implementedKubernetes not yet implementedPodman not yet implementedProxmox LXC incompatible

Exampleexamples/scale-mode

This guide shows you how to throttle an instance’s block I/O when idle on the Docker provider, using the sablier.idle.blkio-* and sablier.active.blkio-* labels:

# compose.yml
services:
  myapp:
    image: myapp:latest
    labels:
      - "sablier.enable=true"
      - "sablier.group=myapp"
      - "sablier.idle.replicas=1"
      # Global relative weight (10-1000)
      - "sablier.idle.blkio-weight=100"
      - "sablier.active.blkio-weight=500"
      # Per-device limits (comma-separate multiple devices: "/dev/sda:10m,/dev/sdb:5m")
      - "sablier.idle.blkio-device-read-bps=/dev/sda:10m"
      - "sablier.idle.blkio-device-write-bps=/dev/sda:10m"
      - "sablier.idle.blkio-device-read-iops=/dev/sda:100"
      - "sablier.idle.blkio-device-write-iops=/dev/sda:100"

In addition to CPU and memory, Docker can throttle block I/O in scale mode. This is useful when an idle workload should keep running but must not compete with active workloads for disk bandwidth.

    flowchart LR
    active["Active<br/>blkio-weight 500"]
    idle["Idle<br/>blkio-weight 100"]
    active -->|session expires| idle
    idle -->|new request| active
  

Labels

• blkio-weight is a relative I/O scheduling weight in the range 10-1000. Values outside that range (or the value 0) are ignored.
• *-bps rates accept Docker-style byte units (10m = 10 MB/s, 100k = 100 KB/s).
• *-iops rates are plain integers.
• Per-device values are path:value pairs; separate multiple devices with commas.
• As with CPU/memory, a limit set on the idle profile is not cleared automatically on wake-up. To restore full I/O, set the corresponding sablier.active.* label (e.g. a higher blkio-weight or a larger rate).

See Applying labels for how each provider expresses labels.